Urdu(اردو) is an Indo-European language which originated in India, most likely in the vicinity of Delhi, whence it spread to the rest of the subcontinent. Other major metropolitan areas with a strong tradition of the language include Hyderabad, Lucknow, and Lahore.

Urdu developed as a vernacular dialect from the interaction between local Indian Sanskrit-derived Prakrits and the languages that were spoken in the courts of the rulers of Indian subcontinent, from the time of the Delhi Sultanate to the Mughal Empire and its succeeding states. The language of the court, and of literature, was usually Persian, while that of religion was Arabic, the language of the Qur'an. This process of the mingling of these languages and the local dialects led to the development of everyday speech that sounded much like today's Urdu and Hindi. There is still a spectrum of dialects spoken in the streets of cities from Lahore and Karachi to Delhi and Calcutta and in the villages all over the region.

Urdu, especially in its less formalized form as it developed from a dialect to a more formal language, has also been referred to as "raikhtha" 1, which literally means "a rough mixture".

The formal language is sometimes referred to as Zaban-e-Urdu-e-Moalla (زبانﹺ اردوﹺ معلہ), which can be translated as "Language of Camp and Court". The word urdu itself means "army", "horde" or "tent" in Turkish. Urdu, the Turkish word ordu, and the word horde (found in several European languages) have the same origin.

It soon became the language of the Mughals, distinguished linguistically from local languages by its large and extensive Arabic-Persian vocabulary (40%) superimposed on a base of grammar, usages and vocabulary that it shares in common with Hindi. The result was what has been called one of the world's most beautiful languages, the "Kohinoor" ("Mountain of Light," a famed native, large and brilliant diamond) of India. It is widely spoken today in both India and Pakistan and all countries having a sizeable South Asian diaspora.

The mix of Urdu and Hindi, forming the Hindustani dialects spoken in northern India and Pakistan, form the second-most-popular 'first' language and second-most-popular 'first or second' language in the world. Urdu by itself is the twentieth most popular 'first' language in the world and the national language of Pakistan.

Taken by itself, Urdū is approximately the twentieth most populous natively spoken language in the world, and is the national language of Pakistan as well as one of the 23 national languages of India.

Urdū also refers to a standardised register of Hindustani termed khaṛī bolī, that emerged as the standard dialect of Urdu. Urdū is often contrasted with Hindi, another standardised form of Hindustani. The primary differences between the two are that Standard Urdū is written in Nastaliq script and draws heavily on Persian and Arabic vocabulary, while standard Hindi is written in Devanagari and has supplemented some of its Persian and Arabic vocabulary with words from Sanskrit. The term "Urdū" also includes dialects of Hindustani other than the standardised languages. Other than these, linguists consider Urdū and Hindi to be the same language. On a conversational level at least, Urdu and Hindi are mutually intelligible.